A numerical analysis of time dependent stress fields ahead of stationary interface cracks at creep regime—Part II. Interface cracks in layered materials

Abstract

In this study, the behavior of stationary interface cracks in layered materials at creep regime in plane-strain condition and pure opening dominated mode-I load state was studied numerically. Cracks located at the interfaces of the transitional layer between the elastic and creeping sectors and cracks at the center of the transitional layer are considered. The role of the layer thickness on the evolution of the stress fields at creep regime is also elucidated. The results indicate that both the location of the interface crack and the extent of the transitional layer strongly influence the amplitude of the stress field ( C ∗ ) at steady-state in layered materials. Also, the time required to achieve steady-state varies significantly with these parameters. The introduction of a transitional layer to the interface of the elastic-creeping bimaterials significantly elevates the stress values ahead of the interface cracks under identical applied load levels at creep regime. Due to large variation in the distribution of the stresses ahead of the crack tip, depending on which side of the transitional layer, the creep growth rates of such interface cracks will be significantly different from each other at creep regime under identical loading for a given layered material.